Hinge actuator and method for adjusting two parts of a hinge actuator relative to each other

ABSTRACT

A hinge actuator includes a first part, a second part, an electric drive, a coupling, and an auxiliary coupling. The first part and second part are configured for connection via the electric drive. The coupling is provided between the first part and the second part such that, in a first position, the first part and the second part are connected via the drive and can be pivoted relative to each other via the drive, and, in a second position, the first part and the second part are not connected to each other via the drive and can be pivoted relative to each other manually. In an embodiment, first stops are included on the coupling and the auxiliary coupling, and second stops are included on the coupling and the first part.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.12/472,935, filed May 27, 2009, which is a continuation of U.S. patentapplication Ser. No. 11/499,201, filed Aug. 4, 2006, now U.S. Pat. No.7,547,855, which claims the benefit of PCT Application No.PCT/NL2005/000080, filed on Feb. 4, 2005, which claims benefit ofNetherlands Application No. 1025434, filed Feb. 6, 2004, and NetherlandsApplication No. 1026014, filed Apr. 23, 2004, which applications arefully incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a hinge actuator, including a hinge actuatorfor use in connection with a mirror adjustment mechanism for a wingmirror unit of a motor vehicle.

SUMMARY

The invention relates to a hinge actuator comprising a first part whichis configured for connection with a second part via an electric drive,wherein the first and the second part are provided with stopscooperating in a pivoting direction for defining a select orpredetermined position of the actuator parts with respect to each other,wherein further a coupling is provided between the first and the secondpart, so that in a first position of the coupling the first part and thesecond part are connected via the drive and can be pivoted relative toeach other with the drive, and a second position in which the first partand the second part are not connected via the drive and can be pivotedrelative to each other manually.

Such a hinge actuator is known, for instance, as used in a mirroradjustment mechanism for a wing mirror unit of a motor vehicle. Thefirst part of the actuator is fixedly mounted on the motor vehicle. Thesecond part supports a mirror housing and can pivot relative to thefirst part to the predetermined position, for instance a fold-inposition to reduce the width of the vehicle, for instance after parking,or a fold-out position for use of the wing mirror unit under normaloperating conditions. The predetermined position is defined by the stopscooperating in the pivoting direction, so that further pivoting isprevented.

The two parts of the hinge actuator can be pivoted both electrically andnon-electrically, for instance manually. By the use of the couplingbetween the two parts, the electric drive can be uncoupled so that apivoting movement of the wing mirror unit not caused by the drive, forinstance upon manual pivoting, does not force any movements of thedrive, and damage to the electric drive, such as fractures in a drivetrain or defects in an electric motor, can be prevented.

It is desired to define the predetermined position of the mirror housingso well that unintended pivoting back is prevented. As a consequence,the influence of external forces exerted on the mirror housing, such asair flowing along the wing mirror unit, for instance gusts of wind ordriving wind, is reduced. By the provision of an additional pair ofstops which cooperate in the predetermined position in an oppositepivoting direction, this problem could be mitigated. In order to enableelectrical pivoting back from the predetermined position, the reactionforce caused by the additional pair of stops should not exceed apredetermined level when pivoting electrically, since the drive must beable to overcome the reaction force.

In addition, however, it is desirable that the mirror housing, uponmanual adjustment to the predetermined position, be secured in such away that a clearly sensible coupling or ‘click’ can be felt and that theforce that is needed to adjust the mirror housing further in thepivoting direction is of the same order of magnitude as the requiredforce for pivoting the mirror housing in a direction opposite to thepivoting direction. To realize this, the reaction forces caused by thestops should be of the same order of magnitude in both directions.However, the electric drive then cannot adjust the mirror housing fromthe predetermined position, unless unacceptably powerful and costlyelectric motors are used, or the reaction forces caused by the stops areso slight that upon manual adjustment no resistance of significance issensed.

An object of the invention is to provide a hinge actuator of the typementioned in the opening paragraph hereof, in which, while preservingthe advantages, the disadvantages mentioned are avoided. An object ofthe invention is to obtain a hinge actuator where, in the case of manualoperation, a clearly sensible coupling can be sensed upon thepredetermined position being reached, and where, with the aid of theelectric drive, still pivoting movement from the predetermined positionin the opposite pivoting direction is possible. To that end, the firstand the second part of the hinge actuator are furthermore provided withstops only cooperating in the second position of the coupling in anopposite pivoting direction, for defining the predetermined position.

As the stops cooperating in the opposite pivoting direction are onlyactive in the second position of the coupling, in which the first partand the second part are not connected via the drive, what is achieved isthat the stops cooperating in the opposite pivoting direction, uponmanual operation can cause a reaction force which is of the same orderof magnitude as the reaction force caused by the stops cooperating inthe pivoting direction. As a result, upon manual operation, a clearcoupling is sensible. Moreover, the electric drive can still pivot thefirst part relative to the second part in the opposite pivotingdirection, also from the predetermined position, since the stopscooperating in the opposite pivoting direction are not active in thefirst position of the coupling, in which the electric drive can pivotthe first and second parts relative to each other.

Also with manual operation, in case of external forces on the hingeactuator, such as wind, undesired pivoting movement is prevented, sincea powerful coupling in the predetermined position has been obtained.

Preferably, the first part of the hinge actuator comprises a base plate,provided with a base shaft, while the second part comprises a supportingframe extending around the base shaft for supporting a mirror housing,so that the hinge actuator can be used in a mirror adjustment mechanismfor a wing mirror unit of a motor vehicle.

By designing the coupling with a coupling ring which is disengageablyrotation-coupled and axially movable relative to the base shaft, thefirst and the second position can be defined in a relatively simplemanner. The coupling ring can, for instance, be disengageablyrotation-coupled with the base shaft by means of a cam constructionwhich permits a pivoting movement upon the occurrence of an externalcouple greater than a pre-set level. Due to the fact that the rotationcoupling of the coupling ring then disengages, the coupling ring alsomoves axially from a first axial position which defines the firstposition to a second axial position which defines the second axialposition. When upon pivoting of the first part relative to the secondpart of the hinge actuator the coupling re-engages, the coupling ringmoves back again to the first axial position. Of course, for reliablydefining the axial positions of the coupling ring, also otherdisengageable constructions can be used, such as, for instance, rollerelements in guide tracks.

By designing the stops cooperating in the opposite pivoting direction insuch a way that the occurring reaction forces are in the same order ofmagnitude as the reaction forces occurring upon cooperation of the stopsin the pivoting direction, what is achieved is that upon manualadjustment of the hinge actuator a clear coupling can be sensed upon thepredetermined position being reached. The force that is needed forpivoting further or back is then in the same order of magnitude.

Advantageously, the hinge actuator can be provided with a switch-offmechanism for switching off the drive, whereby the force needed toovercome the stops cooperating in the opposite pivoting direction is inthe same order of magnitude as the force at which the drive is switchedoff by the switch-off mechanism. What is thereby achieved is that theelectric drive upon the predetermined position being reached, switchesoff automatically, so that the drive is not unduly loaded and prematurewear is prevented. Since the required force for switching off is tunedto the same order of magnitude as the force that is required to overcomethe stops cooperating in the opposite pivoting direction with manualoperation, the user will upon manual adjustment of the hinge actuatorexperience a clear coupling upon the predetermined position beingreached. As desired, the required force for removing the coupling isthen of the same order of magnitude in both directions.

Preferably, the cooperating stops are formed by at least one cam whichis arranged on the supporting frame for traversing a path during thepivoting movement of the supporting frame, and at least one first stoppositioned fixedly with respect to the base shaft, and wherein the stopscooperating in an opposite pivoting direction are formed by the camwhich is arranged on the supporting frame and at least one second stoparranged so as to be axially movable with respect to the base shaft. Inthis way, the cam on the supporting frame cooperates elegantly with boththe first stop which prevents pivoting in the pivoting direction, andthe second, movable stop which prevents pivoting movement in theopposite pivoting direction when the coupling is in the second position.

The invention also relates to a method for adjusting two parts of ahinge actuator relative to each other.

Further advantageous embodiments of the invention are represented in thesubclaims.

The invention will be further elucidated on the basis of exemplaryembodiments which are represented in the drawing. In the drawings:

FIG. 1 is a first perspective view of a hinge actuator according to theinvention in disassembled condition;

FIG. 2 is a second perspective view of the hinge actuator of FIG. 1;

FIG. 3 is a perspective view of a base ring and an auxiliary ring of thehinge actuator of FIG. 1;

FIG. 4 is a perspective view of a gear wheel and a base flange of thehinge actuator of FIG. 1;

FIG. 5 is a schematic perspective view of an alternative embodiment ofthe hinge actuator in disassembled condition;

FIG. 6 is a schematic perspective view of the hinge actuator of FIG. 5in assembled condition with the coupling in the first position; and

FIG. 7 is a schematic perspective view of the hinge actuator of FIG. 6in assembled condition with the coupling in the second position.

The figures are only schematic representations of preferred embodimentsof the invention. In the figures, the same or corresponding parts areindicated with the same reference numerals.

FIGS. 1 and 2 show a preferred embodiment of a hinge actuator 1. Thehinge actuator 1 has a first part, designed as a base part 2, and asecond part, designed as a supporting frame 3, which parts can pivotrelative to each other. The base part 2 can be fixedly connected to amotor vehicle, and has a base flange 4 on which a fixed base shaft 5 isarranged. The base shaft 5 extends along a geometric pivoting axis A ofsubstantially upstanding orientation. The supporting frame 3 is built upfrom modules fixedly attached to each other and extends around the baseshaft 5 and can support a mirror housing which accommodates a mirrorglass, so that the whole can serve as a wing mirror unit of a motorvehicle. During pivoting of the hinge actuator 1, the supporting frame 3hinges about the base shaft 5.

Arranged on the base flange 4 is a base ring 7 which likewise extendsaround the base shaft 5. The side of the base ring 7 remote from thebase flange 4 is at least partly formed as a first cam track 8 to betraversed by a cam 9 which is fixedly attached to the supporting frame 3via a cam ring 10. The cam track 8 comprises a substantially planarportion which is bounded at the ends by two inclined butting faces 8 a,8 b which form stops cooperating with the cam 9 in a pivoting directionfor defining a predetermined position of the actuator parts relative toeach other, such as a fold-in position of the wing mirror unit which issuitable for performing parking maneuvers and a fold-out position fornormal use of the motor vehicle in traffic.

The supporting frame 3 accommodates an electric motor, not shown, and adrive train coupled thereto, which constitute the drive of the hingeactuator. The drive train is further adapted to be coupled with thecoupling ring designed as gear wheel 12, which constitutes a couplingbetween the drive and a driven part of the actuator 1. The gear wheel 12encloses the base shaft 5 and is arranged so as to be axially movablerelative thereto and further, in a first position situated near the baseflange 4, restrained from rotation relative to the base shaft 5. Withthe aid of a biased spring element, not shown, the gear wheel 12 isdriven in the direction of the base flange 4. The gear wheel 12 is inengagement with an output part of the drive train, so that the hingeactuator 1 can be adjusted with the drive.

During manual operation of the hinge actuator 1, the lock againstrotation of the gear wheel 12 with respect to the base shaft 5 isdisengaged by the externally applied force, for instance by uncoupling acam construction 11 arranged between the base flange 4 and the gearwheel 12, as shown in more detail in FIG. 4. The cam construction 11comprises at least one cam 11 a and a cam track lib which arerespectively provided on a flange ring 4 a which is restrained fromrotation relative to the base flange 4, and on the gear wheel 12, orvice versa. As a result, the gear wheel 12 moves axially, against thespring action of the spring element, from the first position to a secondposition, situated farther from the base flange 4, in which the gearwheel 12 is freely rotatable relative to the base shaft 5. In the secondposition of the gear wheel 12, the supporting frame 3 can be manuallypivoted relative to the base shaft 5. This enables a manual pivoting ofthe wing mirror unit relative to the motor vehicle without forcingmovements of the drive. Upon subsequent switching on of the electricdrive, the gear wheel 12 couples with the base flange 4, so thatelectric adjustment is possible again.

The hinge actuator 1 furthermore comprises an auxiliary ring 13 whichencloses the base shaft 5 and, under spring action of the springelement, abuts against the gear wheel 12. The auxiliary ring 13 is shownin more detail in FIG. 3 and, with the aid of cams 14 and recesses 15,is axially movable, though restrained from rotation relative to the basering 7, so that the auxiliary ring 13 can follow the axial movements ofthe gear wheel 12. The side of the auxiliary ring 13 remote from thebase flange 4 is at least partly formed as a second cam track 16 to betraversed by the cam 9 arranged on the supporting frame 3. The secondcam track has inclined butting faces 16 a, 16 b, so that pivoting of thesupporting frame 3 from the predetermined position in the oppositepivoting direction is prevented.

When the gear wheel is in the first position, the hinge actuator 1 canbe adjusted with the aid of the electric drive. The cam 9 of thesupporting frame 3 then traverses a path which is defined by the firstcam track 8, since the second cam track cannot come into contact withthe cam 9 in the first position of the gear wheel 12. Upon reaching abutting face 8 a, 8 b of the first cam track 8, the cam 9 formstherewith a pair of stops cooperating in the pivoting direction, causinga reaction force whereby the electric motor 10 switches off in thepredetermined position. The hinge actuator can pivot back electricallyby activating the electric motor 10 in the opposite pivoting direction.

As described above, manual adjustment of the actuator is possible bybringing the gear wheel 12 in the second position, as a result of whichthe electric drive is uncoupled. The gear wheel 12 further pushes theauxiliary ring 13 in the direction directed away from the base flange 4,so that the second cam track 16 can also limit the path of the cam 9.Upon manual pivoting of the hinge actuator 1, the cam 9 will again form,together with a butting face 8 a, 8 b of the first cam track 8, a pairof stops cooperating in the pivoting direction, thereby preventingfurther pivoting in the pivoting direction. The occurring reactionforces are a signal to the user that further pivoting is probablyundesired, because a position which is desired for the user of the motorvehicle has already been obtained or because further pivoting is notpossible in terms of construction technique. Also pivoting back is nowprevented by the cam 9 which, together with a butting face 16 a, 16 b ofthe second cam track 16, forms a pair of stops cooperating in theopposite pivoting direction. As a result, the person performing thepivoting movement experiences a clearly noticeable coupling in thepredetermined position of the supporting frame 3 with respect to thebase shaft 5. Owing to the specific shape and dimensions of the buttingfaces 8 a, 8 b, 16 a, 16 b, the required force to overcome the two pairsof cooperating stops is in the same order of magnitude. The cam 9 isoriented so broadly that cooperation with the butting faces of both thefirst and the second cam track 8, 16 is possible. Instead of oneintegrated cam 9, however, two cams may be arranged which, if desired,can include an angle relative to each other. Also in the case of otherpivoting movement of the hinge actuator, not caused by the drive, forinstance upon contact with a foreign object, such as a pillar, theabove-outlined interplay of forces occurs.

The hinge actuator 1 furthermore comprises a current limiting circuitwhich serves as a switch-off mechanism. When, upon the supporting frame3 and the base shaft 5 reaching the predetermined position, the electriccurrent in the electric motor increases in order to generate asufficient couple, the current limiting circuit switches off theelectric motor at a predetermined current intensity, so that damage tothe electric motor is prevented. The butting faces 16 a, 16 b of thesecond cam track 16 are so designed that overcoming the reaction forcescaused with the cam 9 in the predetermined position of the hingeactuator would generate such a large current in the electric motor thatthe current limiting circuit would enter into operation and switch offthe electric motor.

Optionally, the hinge actuator may furthermore be provided with aresilient ring for driving the auxiliary ring in the direction of thebase flange in order to prevent stops being able to cooperate in theopposite pivoting direction when the first and second part of theactuator are connected with each other via the drive.

FIGS. 5, 6 and 7 show an alternative preferred embodiment of the hingeactuator 101. The hinge actuator 101 has a first part, designed as abase part 102, and a second part, designed as a supporting frame 103,which parts can pivot relative to each other. The base part 102 can befixedly connected to a motor vehicle, and has a base flange 104 on whicha fixed base shaft 105 is arranged. The supporting frame 103 is built upfrom modules fixedly mounted on each other, extends around the baseshaft 105 and can support a mirror housing in which a mirror glass isincluded, so that the whole can serve as a wing mirror unit of a motorvehicle. During pivoting of the hinge actuator 101, the supporting frame103 hinges about the base shaft 105.

Formed on the base flange 104 is a cam track 108 which can be traversedby a cam 109 which is fixedly mounted on the supporting frame 103. Inthe figure, for the sake of clarity, this part of the base frame isrepresented as a separate cam ring 110. It will be clear that the camring 110 may be integrated with the bottom of the supporting frame 103.The cam track 108 comprises a substantially planar portion which isbounded at the ends by an inclined butting face 108 a which cooperatesin the pivoting direction indicated by the arrow P with a correspondingstop surface 109 a of the cam 109. The stop surfaces 108 a, 109 a formcooperating stops for defining in a first pivoting direction apredetermined position of the actuator parts 102,103 with respect toeach other. In the figure, this is represented as a fold-out position ofthe wing mirror unit during normal use of the motor vehicle in traffic,which is defined in the fold-out direction.

Included in the supporting frame 103 is an electric motor 120 with adrive train 121 coupled to it, which constitute the drive of the hingeactuator. The output part of the drive is formed as a gear wheel 112which is arranged as a coupling ring around the base shaft 105. The gearwheel 112 and the base shaft 105 together constitute a coupling 111 sothat, in the first position of the coupling, the base part 102 and thesupporting frame 103 are connected via the drive and can be pivotedrelative to each other with the drive, and in a second position, thebase part 102 and the supporting frame 103 are not connected via thedrive and can be pivoted relative to each other manually.

The gear wheel 112 encloses the base shaft 105 and is so arranged as tobe axially movable relative thereto. In a first position, situatedaxially closer to the base flange 104, the gear wheel 112 is furtherrestrained from rotation, that is, rotation-coupled with respect to thebase shaft 105.

During application of an external force on the hinge actuator 101, as inthe case of manual operation, the lock against rotation of the gearwheel 112 relative to the base shaft 105 can be disengaged by uncouplingthe coupling 111 between the gear wheel 112 and the base shaft 105.

To that end, the coupling 111 comprises, on the one hand, threetwo-topped profiles 122 arranged on the circumference of the base shaft105 and, on the other hand, cams 123 reaching downwards with respect tothe gear wheel 112 for cooperation with the two-topped profiles. In thefirst position of the coupling, the gear wheel 112, in a first axialposition, is supported axially on the base shaft 105 and locked againstrotation in that the cams 123 are each lodged in valleys 124 betweentops 125 of the two-topped cam track profiles 122. In the first positionof the coupling 111, the gear wheel 112 is axially movable from a firstaxial position, in an axial direction directed away from the base flange104, to a second axial position.

When under the influence of an external force the supporting frame 103is rotated about the base shaft 105, the gear wheel 112 is carried alongby the drive train 121, and the cams 123 are guided axially upwards viathe flanks of the tops 125 contiguous to the valley 124. After passingthe tops 125, the cams will be guided downwards under the action of acoil spring 106 arranged around the base shaft 105, along the inclinedflanks of the two-topped profile 122 remote from the valleys, down ontoa top surface of an auxiliary coupling ring 126 arranged around the baseshaft 105 between the gear wheel 112 and the supporting frame 103, sothat the gear wheel 112 reaches a second axial position in which it isfreely rotatable relative to the base shaft 105. The function of theauxiliary coupling ring 126 will be further elucidated hereinafter.

The coupling 111 enables a manual pivoting of the wing mirror unitrelative to the motor vehicle without forcing movements of the drive.

By the use of the coupling 111, the supporting frame 103 can thereforebe pivoted around the base part through both electric drive and manualoperation. The fold-out position is then defined in a first pivotingdirection, i.e. towards the fold-out position, by cooperation of thestop surfaces 708 a, 709 a.

During pivoting in the first direction towards the fold-out position,the electric operation can be switched off with the aid of a currentlimiting circuit 130. When, upon reaching the predetermined position ofthe supporting frame 103 through cooperation of the stops 108 a, 109 a,the electric current in the electric motor increases, the currentlimiting circuit 130 switches off the electric motor at a predeterminedcurrent intensity, thereby preventing damage to the electric motor ordrive train.

Under the influence of an external force, the cooperating stops 108 a,109 a can be overcome against the action of the spring 106, so that thebase frame 103 can be pivoted further in the direction of the arrow P toa fold-over position. The supporting frame 103 can then be pivoted backboth with the aid of the electric drive and manually.

When the first and the second part are connected via the drive, thefold-out position is defined in the opposite pivoting direction in thatthe drive prevents pivoting.

For defining the fold-in position in the case of manual operation in theopposite pivoting direction, i.e. in the inward pivoting direction, thehinge actuator 101 is equipped with an auxiliary coupling ring 126 whichis arranged around the base shaft 105. The auxiliary coupling ring 126is arranged between the gear wheel 112 and the supporting frame 103. Theauxiliary coupling ring 126 and the mirror supporting frame 103 areprovided with auxiliary stops 127,128 cooperating only in the secondposition of the coupling 111 in the opposite pivoting direction. Theseauxiliary stops therefore constitute the stops for defining thepredetermined position in the opposite pivoting direction. The auxiliarycoupling ring 126 is arranged around the base shaft 105 so as to beaxially movable and rotation-coupled. The auxiliary stops 128 are formedby stop surfaces 128 a on two cam tracks 128′ which are provided on theundersurface of the auxiliary coupling ring 126. The auxiliary stops 127are formed by stop surfaces 127 a which are provided on two upwardlyreaching cams 127′ on the supporting frame 103. As will be elucidatedhereinafter, the cam tracks 128′ and the cams 127′ cooperate to definethe fold-out position in the fold-in direction when as a result of anexternally applied force the coupling is in the second position, and thecams 123 of the gear wheel 112 therefore rest on the top surface of theauxiliary coupling ring 126. It will be clear that the cams 127′ and thecam tracks 128 can also be interchanged.

The hinge actuator 101 further comprises an intermediate ring 129,arranged around the base shaft, which is under axial action of thespring 106. In a first position of the coupling 111, the intermediatering 129 is supported directly on the supporting frame 103. In thesecond position of the coupling 111, the upper surface of the gear wheel112 is in the second position, which is situated axially farther fromthe base flange 104 than the first position. The intermediate ring 129is then supported on the upper surface of the gear wheel 112. As aresult, when the gear wheel 112, as described above, has been broughtinto the second position upon manual pivoting of the supporting frame103, the auxiliary coupling ring 126 will become subject to springaction. What is thus achieved is that in the first position of thecoupling, in which the gear wheel 112 is supported on the base shaft 105while the auxiliary coupling ring is freely movable with limited travel,the cam tracks 128′ on the auxiliary coupling ring 126 do not cooperateunder spring action with the cam tracks 127′. As a result, the stopsurfaces 127 a, 128 a will not cooperate as stops duringelectrically-driven inward pivoting from the fold-out position. Uponelectrically-driven inward pivoting, the auxiliary coupling ring 126will be moved axially upwards and permit pivoting without resistance ofsignificance.

What can optionally be achieved by providing a slight friction betweenthe auxiliary coupling ring 126 and the base shaft 105, is that the stopsurfaces 127 a, 128 a are axially spaced apart during normal (electric)operation and hence do not touch upon being pivoted relative to eachother.

In the second position of the coupling, however, the auxiliary couplingring 126 is under downward spring action via the gear wheel 112, whichis now in the second position. The auxiliary coupling ring 126 transmitsthe spring force to the supporting frame 103, viz. in that the auxiliarycam 127′ is pressed onto the auxiliary cam track 128′. When thesupporting frame is pivoted further to the predetermined position, theauxiliary cam 127′ will follow the auxiliary cam track 128′ and beguided along auxiliary stop surface 128 a to a higher supporting surface128″ of the cam track 128′.

As a result, the auxiliary coupling ring 126, together with the gearwheel 112, will undergo a downward movement, i.e. towards the baseflange 104. In the process, however, the two preferably remain underspring action. The downward movement is limited in that the stopsurfaces 127 a and 128 a cooperate in the opposite pivoting direction,and also in that stop surfaces 127 a of auxiliary cams 127′ andsupporting surfaces 128″ of the cam tracks 128′cooperate, so thateventually the predetermined position is defined. As the fold-outposition is approached during folding out, this will be experienced bythe pivoting person as a clear ‘click’.

After a manual pivoting to the fold-out position as described above,then, upon manual operation in the opposite pivoting direction, firstthe stops 127, 128 will have to be overcome against the action of thespring 106, so that a clear ‘click’ can be felt again. The auxiliarycoupling ring 126 is then pressed upwards, together with gear wheel 112,against the spring action. In this way, therefore, it is possible uponmanual operation to feel a clear ‘click’ both upon outward pivoting tothe fold-out position and upon pivoting back from the fold-out position,while this ‘click’ can remain absent in the case of electrical pivotingback.

The invention is not limited to the exemplary embodiments describedhere. Many variants are possible.

Thus, the coupling ring designed as gear wheel can be designeddifferently, for instance as a ring which constitutes a disengageablecoupling between a driven part of the electric drive and a first orsecond part of the hinge actuator.

Also, the cam may be fixed on the base ring, with butting faces providedon the supporting frame and the auxiliary ring. The auxiliary ring isthen locked against rotation with respect to the supporting frame.Furthermore, the cam tracks and the cam can be of eccentric or otherdesign.

Furthermore, the switch-off mechanism, instead of being designed as acurrent limiting circuit, can also be designed with the aid of adifferent mechanism, for instance with the aid of a friction coupling.

Such variants will be clear to those skilled in the art and areunderstood to fall within the scope of the invention as set forth in thefollowing claims.

What is claimed is:
 1. A hinge actuator comprising: a first part; asecond part; an electric drive, the first part configured for connectionto the second part via the electric drive; a coupling provided betweenthe first part and the second part such that in a first position thefirst part and the second part are connected via the drive and can bepivoted relative to each other via the drive, and in a second positionthe first part and the second part are not connected via the drive andcan be pivoted relative to each other manually; and an auxiliarycoupling; wherein first stops are included on the coupling and theauxiliary coupling, and second stops are included on the coupling andthe first part; the first and second stops only cooperate in the secondposition of the coupling in an opposite pivoting direction and areconfigured to define a select or predetermined position, the first andsecond stops are not active in the first position of the coupling, andthe first and second stops are only active in the second position of thecoupling.
 2. The hinge actuator according to claim 1, wherein the firststops and second stops are configured in the opposite pivoting directionso that occurring reaction forces associated with their cooperation arein the same order of magnitude as occurring reaction forces associatedwith their cooperation in the pivoting direction.
 3. The hinge actuatoraccording to claim 1, further comprising a switch-off mechanism forswitching off the electric drive, wherein the force for overcoming thefirst stops is at least the same order of magnitude as the force atwhich the drive is switched off by the switch-off mechanism.
 4. Thehinge actuator according to claim 3, wherein the switch-off mechanismcomprises a current limiting circuit, and the electric current of thecircuit for overcoming the first stops is at least the same order ofmagnitude as the current at which the current limiting circuit switchesoff the drive.